Thomas hancock



T. HANCOCK. MANUFACTURE OF METAL REFLECTORS, MIRRORS, AND OTHER METAL ARTICLESIHAVING A REFLECTING SURFACE 0R SURFACES.

APPLICATION FILED MAY 3.1918.

1 336,224, Patented Apr. 6, 1920.

I UM 5 yfjllcu UNITED STATES PATENT orrroa.

THOMAS HANCOCK, OF BOW, ENGLAND, ASSIGNOR TO THE REFLECTO-METAL COMFANY,

, LIMITED, OF LONDON, ENGLAND.

MANUFACTURE OF METAL REFLECTO-RS. MIRRCRS, AND OTHER METAL ARTICLES HAVING A REFLECTING SURFACE OR SURFACES.

Specification of Letters Patent.

Patented Apr. 6, 1920.

Application filed May 3, 1918. Sefial N 0. 232,252.

To all whom it may concern:

Be it known that I, THOMAS HANCOCK, a subject of the King of Great Britain and Irelandyresiding at 108 The Grove, Bow, in the county of Essex, England, have inventednew and useful Improvements in the Manufacture of Metal Reflectors, Mirrors, and other Metal Articles Having a Reflecting Surface or Surfaces, of which the following is a specification.

The invention relates to the manufacture of metal reflectors or mirrors, that is to say of artlcles having a reflecting surface, and

conslsts of a method by which such articles surface, which is made of a shape the reverse of the reflecting surface of'the reflector or mirror to be'madef For instance, in the case-of a parabolic reflector the main part of the former, that is to say the part which determines the shape of the article'to be manufactured, would consist of a head made of a shape the reverse of the inner surface of the parabolic reflector, while the remainder of the former would consist of a connected stem. The necessary former having been made, a bath of the metal or alloy to be used is prepared, and is maintained, during the process of manufacture, at a constant temperature, which is slightly above the melting point of the metal or alloy. After the removal of the scum from the surface of the bath of metal, so that a perfectly clean and bright metal surface is presented to the former, the head of the former is dipped into the bath of molten metal to a depth such that the part of the former which determines the shape of the article to be manufactured is immersed in the bath. The former is then immediately withdrawn, and will'be found to be covered with a coating of the metal. The former with its adherent coating is allowed to cool,

and this quickly takes place. On separation from the former the coating or shell will be found to have a surface highly polished Where reviously in contact with the highly polished surface of the former. When the former has become cooled its polished surface is carefully wiped to render it clean and bright for use again in the manner described.

The metal shells formed as above described, after their rough edges have been removed, and, if necessary, cut to any particular shape, may be secured to backin s of stout metal or be otherwise used accor ing to circumstances. t

in practice a number of formers may be employed so as to enable a relatively great number of articles to be manufactured at a time. i

The former is made of a material, adapted to take a high polish andto Withstand the heat of the bath of molten metal. Thus the former cools the metal in contact with its immersed surface. Materials from which the formers may be made are for example annealed glass, porcelain and china, particularly the first named. v

.. The metals or alloys which may be utilized in the. manufacture of the reflectors or mirrors, apart from the fact that they must be capable of having a reflecting surface imparted to them, must be such that they will former and must be such that the coating produced will not develo cracks or fissures as it cools. Metals and a loys which can be employed are for example those of low melting point such as tin, an alloy of tin and lead containing a small percentage of copper, antimony or other metal which will exert a hardening effect on the tin, or tin and lead and prevent deterioration of the reflecting surface under normal atmospheric conditions.

The invention is illustrated by the accompanying drawings.

Of these drawings, Figure 1 is a side view of one shape of former, and Fig. 2 is a section of a metal reflector formed by dipping said former in a bath of molten metal or alloy. Figs. 3 and 4 are views, correspond be cooled at the surface of contact with the In both cases a is the head or main part of the former, which is provided with a smooth and highly polished surface, I) are the stems by which the formers are heldwhile they are dipped in a bath of molten metal or alloy, and c is a metal reflector formed by said dipping.

while adherent to the former, one or more times in the bath.

Having now described my invention, what I have invented and desire to secure by Letters Patent of the United States is as follows 1. A method of making metal reflectors or mirrors, consisting in the momentary immersion in molten metal of a former having that part of its surface intended to be immersed highly polished and formed of a shape the reverse of that of the reflecting surface of the reflector or mirror to be produced, and the separation of the solidified coating of metal from the immersed surface of the former after withdrawal of the latter from the molten metal.

2. A method of making metal reflectors or mirrors, consisting in the momentary immersion in molten metal or analloy of low melting point of a former having that part of its surface intended to be immersed highly polished and formed of a shape the reverse of that of the reflecting surface of the reflector or mirror to be produced, and

the separation of the solidified coating of metal from the immersed surface of the former after Withdrawal of the latter from the molten metal.

3. A method of making metal reflectors or mirrors consisting in the repeated momentary immersion in molten metal of a former having that part .of its surface intended to be immersed highly polished and formed of a shape the reverse of that of the reflecting 7 surface of the reflector or mirror to be produced and the separation of the solidified coating of metal from the repeatedly immersed former after its withdrawal on final immersion in the moltenmetal.

4. A method of making metal reflectors or mirrors consisting in the momentary immersion in molten metal after the scum has been removed from its surface to present a clean face of metal, of a former having that part of its surface to be immersed highly polished and formed of a shape the reverse of that of the reflecting surface of the' reflector or mirror to be produced and the separation of the solidified coating of metal from the immersed surface of the former after its withdrawal from the molten metal.

5. A new article of manufacture being a solidified self-supporting film of metal, the

whole of which is of the physical character of metal solidified directly from its molten state without mechanical treatment of any kind, the said solidified self-supporting film having one of its faces a mirror.

6. A new article of manufacture being a solidified self-supporting film of metal of low melting point, the whole of which is of the physical character of metal solidified directly from its molten state without mechanical treatment of any kind, the said solidified self-supporting film having one of its faces a mirror.

In testimony whereof I have signed my name to this specification.

THOMAS HANCOCK. 

